This project is considering the assembly and organization of collagen fibers from several points of view. The assembly of the molecule from its constituent polypeptide chains is being studied via cell free synthesis in a reticulocyte lysate system. Translation in the presence of rough microsomes allows processing and molecular assembly. The question under investigation is: When do the chains assemble, before or after release and completion of translation? The assembly of completed molecules into fibrils is being examined via pH-jump and thermal assembly processes as a function of specific features of telopeptide sequence. Physical chemical studies are being used to determine the mechanism of fibril initiation and growth. Basement membrane molecules of known states of completeness are also being studied for in vitro organization into membranous structures.